personal service of a statutory demand,ilegal by curtis.

hi there, i have a court case on the 15 of this month against royal sun alliance,the solicitors in quetion are curtis from plymouth.
they hve placed a creditors notice on my flat for 14750 pounds.i only found this out a few months ago when the court wrote to me advising me of this,before that i knew nothing of any problems,i have lived at my current flat for 11 years, and have been working for my employers(the queens store plc,i cant give the name .)for seven years.to the points:
1)the property they mention 12 grenford road,was never owened by me,i owend 12 greenfield road,grenford road is in ealing i belive,i've alwasys lived in north london.can this be a problem for them in court?
2)the date 1991 28th june wa the sale of the property,isn't statutory barred?
3)they claim they served upon me a personal service of a statutory demand in person at1700hours on the 5/12/01,now i find this shockin as i have evidence from my employers that i was at work at the time of alleged service,how can they claim this??i believe they
waited two years to force the notice in the hope i would have no evidence,as in fact i was very lucky to find that,they only hold record for two years than they bin them.i sent the court as evidence
a letter from personall departmen stamped by them and a copy of the rota sigened by my manager two years ago.
4)the server says in the court files:that i did on wednesday the 5th day of december of 2001 before 1700 hours at xxx xxxxxx road london xx xxx personally serve the above-named debtor with the demand dated 17 of nov 2001.
now he is saying that he seved me ,right??should i worry?any help
would be apreciated,thanks.